if you are recording in soundcard mode there is no metadata, you have to update the track title manually.

with mixxx in shoutcast mode (v1 source), the files must have tags that mixxx can read, it's not as robust as winamp.

don't depend on what is displayed in the yp (or other secondary listings) to check metadata updates, you have to query the server that the source is connected to (/admin.cgi). view the history and log... track title updates always appear in the log wether the server is public or not.